What is better 12 V or 24 V charger? for a 150Ah Battery. Power input: 220V, 50 Hz.?

Question

I am looking to make a back up power unit for my house (in case of power supply failure) to run an electrical load of about 400 Watts (220V, 50 Hz.). Power input to charger is the same: 220V / 50 Hz.

Plan to buy a 150Ah Lead Acid Battery and hook it up with charger and inverter.

What Charger is better 12V/24V? Does it affect/depend upon the battery type?

How long do you think the supply would last?

Thanks for your help in advance.

Answer 1

It depends on the type of DC to AC convertor. If its input is designed for 12 volts DC,you need a 12 volts battery with 150AH or higher AH rate. Then you need a 12 volts battery charger output at least 1.5 amperes (10% of current rate) to charge the battery up to fully charged in 16 hours.

How long the supply would last? It depends on how good and how effiency the DC to AC convertor that you have. Some poor cheap design waste a lot of electricity and turn into heat.

Therefore,I estimate you might have 2 to 4 hours to support an

output of 220 volts AC at 400 watts load. Do a test load or read its specification.

NEVER USE A 24 CHARGER TO CHARGE A 12 BATTERY,IT SHALL EXPLODE!!!!

Answer 2

12 volt battery, use 12 volt charger

24 volt battery (or 2 - 12v batteries in series), use 24 volt charger

A 150 amp-hr battery is good for about 1500 w-hrs of energy.

At the 400 watt number, you would get 1500/400 = 3+ hours out of the battery.

Be sure you get a sealed battery as fumes from a Lead Acid battery can be toxic.

Inverter, get the better one that has sine wave output, or many of your appliances won't work. Also ignore the VA rating and get one that has a wattage rating of 500 watts or higher.

Answer 3

It does depend on the battery type.  If it is a 12 volt battery use a 12 volt charger, if 24, use a 24.  How long it will last depends on how much you have running, larger appliances tend to take more power as well.

Answer 4

Higher the voltage the better. 400 watts at 12 volt would end up being say  450 after lose and inefficiency. That's 40ish amps. You would need a large wire to run this type of amps.

24 would be better you could use much smaller wire.. But  you would need to get a 24v charger and inverter.

Remember if you buy a cheap inverter  you can't run electronics on it or risk burning them out. Better (full wave) inverters cost a lot.

150 ah at 12volts pulling 450 watts  is 12/450=37.5 amps

150ah (amps hours) would be 37.5/150ah=4 hours of run time

24volts 450wats 150ah = about 9 hours. (using the math above)

I should note that batteries don't come in 12volt 150ah and 24volt 150ah at the same price. In the same price range you would really see

12volt150ah

24volt75ah.